Here is a video with the exact same problem in the PCV system but on a Cruze. The valve cover is different but the valve is the same hidden inside the valve cover on the Aveo. The guy in the video forced opened (broke the plastic housing) the valve to see why it failed. I have the exact same problem on my 09 Aveo right now. I'm waiting for the new valve cover kit.
https://www.youtube.com/watch?v=NhuxYYCjzuQ